Riveting machines



May 15, 1962 A. SHACKELL RIVETING MACHINES 2 Sheets-Sheet 1 Filed Jan.29, 1960 M G F Mm R Nw m R N M E r rm a; mu WW 9 May 15, 1962 Filed Jan.29, 1960 A. SHACKELL 3,034,676

RIVETING MACHINES 2 Sheets-Sheet 2 3,034,676 Fatented May 15, 19623,034,676 RIVETING MACHINES Arthur Shackell, Weston Turville, England,assignor of one-half to The Bifurcated & Tubular Rivet Company Limited,Aylesbury, England, a company of Great Britain Filed Jan. 29, 1960, Ser.No. 5,444 Claims priority, application Great Britain Oct. 21, 1959Claims. (Cl. 218-2) This invention relates to riveting machines, whichterm is intended to include machines for applying similar fixingdevices, e.g. tacks.

In one form of known riveting machine, rivets (i.e. rivets, tacks orsimilar fixing devices) are fed one at a time into a holder which ismovable towards a workpiece to be riveted as a riveting plunger pushes arivet through the holder into the workpiece. One object of the presentinvention is to provide a machine of this form, in which the holder isheld stationary until the plunger has engaged the head of the rivet andis then moved at a slower rate than the plunger to come to rest clear ofthe workpiece before the plunger pushes the rivet through the holderinto the workpiece. A further object is to provide a machine in whichmovement of the holder, during the riveting stroke, is arrested withoutdamage to the machine if the holder engages an obstruction.

According to the invention, there is provided a riveting machine,comprising a movable plunger, a holder adapted to support a rivet orsimilar fixing device between said plunger and a workpiece location,first means operable to move said plunger into engagement with the rivetand thereafter drive the rivet through a workpiece, and second meansoperable after the plunger has engaged the rivet to move said holdertowards the workpiece at a speed slower than that of the plunger, theholder being maintained stationary prior to said engagement.

The invention will be described in relation to one embodiment thereofand with reference to the accompanying drawings, in which:

FIGURES 1 and 2 show side and end views respectively of the embodiment,FIGURE 2 being partly in section. FIG. 1a is a fragmentary view of amodification of the embodiment according to FIGS. 1 and 2.

Referring to the figures, a plunger bar 1 and a holder bar 2 areslidably mounted in a rigid frame member 3. At their lower ends, theplunger bar carries a plunger 4 and the holder bar carries, through apair of leaf-spring arms 5, a holder 6. The arms 5 are secured to theholder bar by a screw and wing-nut assembly 7. Rivets are fed one at atime to the holder down a chute 8 and, as such an arrangement iswell-known it will not be further described.

An operating lever 9, actuated by any suitable known means (not shown),is pivoted to the frame member at 10 and extends to engage at one end 9ain a channel-sectioned member 11 integrally formed at the upper end ofthe plunger bar. Said end of the lever 9 is of part-circular shape asshown, within the member 11, and pivoting of the lever effects slidingmovement of the plunger bar relative to the frame member.

The upper end of the holder bar 2 is grooved to receive one end of acontrol lever 12, which lever normally rests on a peg-like projection 13secured to the operating lever 9 and located between the pivot 10 andthe end 9a of the lever 9. The other end of the lever 12 is urgeddownwardly by a tension spring 14 connected between the lever 12 and apost 15 fixed on a rigid frame 3. Lever 12 is provided with a dependingabutment 16 which projects downwardly beyond the groove in the holderbar and serves to limit pivoting of the control lever relative to saidbar.

Sliding movement of the holder bar 2 relative to the frame member 3 islimited by two stops 17 and 18 secured to the bar. Stop 17 abuts theunder side of the frame member to limit upward movement of bar 2 andstop 18 abuts the top side of said member to limit downward movement ofthe bar.

The plunger bar 1 and holder bar 2 are both shown in their uppermostpositions ready to commence a riveting stroke. With a rivet (not shown)positioned in the holder 6, operating lever 9 is pivoted so that theplunger bar, with the plunger 4, moves downwards. Consequent downwardmovement of the projection 13 permits control lever 12 to pivot relativeto the holder bar, under the force of spring 14, until abutment 16 oflever 12 engages the holder bar. Thus, during the initial movement ofthe plunger 4 the holder 6 remains stationary, the engagement ofabutment 16 with the holder bar being arranged to coincide withengagement of the plunger with the head of the rivet.

As projection 13 continues downwards, the control lever 12 acts as afixed extension of the holder bar 2 and the latter, with the holder 6commences to move downwards under the force of spring 14. Due to thelocation of projection 13, the holder moves at a slower speed than theplunger thereby allowing the plunger, with the rivet, to move throughthe holder. Towards the end of the riveting stroke, stop 18 abuts theframe member and prevents further movement of the holder so that, whenthe stroke is completed, relative positions of the plunger and bolderare as indicated by broken lines at 4a and 6a respectively.

Although not shown, it will be appreciated that a suitabie anvil isprovided below the plunger so that, with a workpiece on the anvil, therivet is secured in position in the workpiece at the end of the rivetingstroke.

On the return stroke, abutment 16 remains in engagement with the holderbar 2 until stop 17 abuts the frame member. :Further upward movement ofthe holder bar is then prevented and the control lever 12 pivots to theposition shown.

One advantage of a machine according to the invention is that, if theholder meets an obstruction (e.g. a misplaced workpiece) during itsdownward travel, it will resist the force of the spring 14 and stop,projection 13 moving out of contact with the control lever 12. Duringthe following return stroke, the projection will re-engage the lever andthe holder will be lifted clear of the obstruction.

According to a feature of the invention, the effective diameter of theprojection 13 may be adjusted, thereby altering the distance betweenabutment 16 and the holder bar. This enables the time delay betweencommencement of movement of the holder and plunger bars to be altered.One means of adjusting the projection diameter is by the use of a sleeve13a adapted to fit over the projection 13 between it and the controllever 12. With such an adjustable arrangement, the time delay can bechosen so that the shank of a rivet projects visibly through the bottomof the holder before the latter reaches its lowest position. This willpermit an operator readily to locate a pierced workpiece on the rivetprior to riveting.

What is claimed is:

1. A riveting machine, comprising a movable plunger, a holder adapted tosupport a rivet between said plunger and a workpiece location, firstmeans operable to move said plunger into engagement with the rivet andthereafter drive the rivet through a workpiece, second means controlledby said first means to be operated after the plunger has engaged therivet, said second means moving said holder towards the workpiece at aspeed slower than that of the plunger, the holder being maintainedstationary prior to said engagement, a plunger bar carrying said aplunger, and a holder bar carrying said holder, said bars being mountedlongitudinally slidable, said first means including an operating leverpivoted to a fixed pivot and engaging said plunger bar, pivoting of theoperating lever producing longitudinal movement of the plunger bar, andsaid second means including a control lever pivoted to said holder barfor an initial limited pivotal movement relative thereto, means forpositioning the control lever in dependence upon a pivotal movement ofsaid operating lever so that the holder bar is maintained stationaryduring said initial limited pivotal movement of the control lever, andspring means moving said holder bar longitudinally in the same directionas the plunger bar upon completion of said limited pivotal movement ofthe control lever.

2. A machine according to claim 1, wherein said operating lever carriesa projection located between said fixed pivot and the point ofengagement with the plunger bar, said control lever extending past saidprojection towards the fixed pivot, said spring means are maintainingthe control lever in contact with said projection.

3. A riveting machine, comprising a rigid frame member, plunger andholder bars supported by the frame member parallel to each other andindividually lengthwise slidable relative thereto, a plunger secured atone end of the plunger bar, a holder secured at a corresponding end ofthe holder bar and serving to locate a rivet in the path of the plunger,an operating lever pivoted to the frame member and coupled to the otherend of the plunger bar for reciprocating the plunger relative to aworkpiece by pivoting said lever, a projection extending from theoperating lever and located between the pivot of said lever and thecoupling point thereof with the plunger bar, a control lever pivoted tothe holder bar adjacent said other end of the plunger bar and slidablyengageable intermediate its ends with said projection, stop meansdefining a limit position for pivotal movement of the control leverrelative to the holder bar, spring means urging the control lever intocontact with said projection so that the control lever tends to move asthe operating lever pivots, and further stop means defining limitpositions for a sliding movement of the holder bar and the holder ineither direction; whereby, on pivoting of the operating lever, theplunger is moved from an initial position towards the holder, the latterremaining stationary due to pivoting of the control lever, and when thecontrol lever reaches the limit of its pivoted movement, the holder ismoved from one of its limit positions in the same direction as but at aslower speed than the plunger, and when the holder reaches its otherlimit position it becomes stationary while said projection is held outof contact with the control lever.

4. A machine according to claim 3, comprising a control means forvarying the angle of the pivotal movement prior to reaching its limitposition.

5. A machine according to claim 4, wherein said control means comprisesa sleeve of a selected outer diameter fitting over said projection so asto lie between the projection and the control lever; whereby the angleof pivot of the control lever prior to reaching its limit position iscontrolled by the outer diameter of said sleeve.

References Cited in the file of this patent UNITED STATES PATENTS2,373,436 Treciokas Apr. 10, 1945 FOREIGN PATENTS 561,726 Great BritainJune 1, 1945

